FUN CITI: Newcomer Jason Bay high-fives in the Mets dugout yesterday as the Amazin's got off to a fresh start after last year's disaster -- beating the Marlins 7-1 on Opening Day at Citi field. Photo: UPI

This is the healing power of Opening Day, the hidden magic of a fresh start. How great would it be if every year you could start out at 0-0? You’d be out of that awful mortgage payment. Your debt would disappear. Your student loans would vanish. All the stupidities assembled every 12 months, tied and tossed in a trash can.

You can’t do that.

But David Wright did, with one flick of his wrist. Johan Santana did, throwing 103 vintage pitches. Gary Matthews did, catching everything hit his way in center field, a task made especially valuable when you saw the adventures everyone else seemed to be having in the Flushing wind.

And the Mets did. It is one game, one out of 162, and it’s worth noting that the Mets won their first two games last year before losing 92 of their final 160. A lot can happen between April and October, and most of it did to the Mets in 2009. But nobody was much inclined to talk about 2009 when this 7-1 victory was official yesterday; there was no need to.

Healing power. Hidden magic.

“We’re out of the gate,” Jerry Manuel, the manager, said with a wide grin that looked so much different from the happy faces he was forced to slap on every day last year. “But we haven’t gone anywhere yet.”

For so much of the past year, Mets fans had to close their eyes and hold their breath and swallow a pageant of indignities, had to endure a Yankees-Phillies World Series, had to see the Mets shed a few million dollars in payroll by taking a pass on every available arm. Had to wince as the Mets’ Banana Peel Express rumbled on, claiming Carlos Beltran’s knee and Jose Reyes’ thyroid, even Kelvim Escobar’s shoulder.

There were times you could believe that not even Opening Day could ease what ailed Mets fans. Yet 41,245 of them jammed Citi Field on a Chamber of Commerce afternoon, came with the same idea Jeff Francoeur brought with him before contributing a couple of RBIs:

“Last year,” he said, “is last year. It’s over. It’s done. There’s nothing we can do about last year, so there’s no reason not to just think about this year.”

Added Wright: “After everything this team has been through, we know that when you have a chance to win a game, you win that game, and you don’t worry about anything else you’ve done other than that.”

Wright gave everyone in the yard an early Fan Appreciation Day gift, launching a Josh Johnson pitch over the yellow Caesars sign just inside the orange right-field fair pole. How bad did last year go? No Met discovered that inviting patch, but Chase Utley did, inspiring Mets broadcaster Gary Cohen to playfully name the area after the Phillies’ second baseman.

When Wright made contact, the reaction was immediate and it was loud. When Santana retired the Marlins 1-2-3 in the top of the first, the reaction was sustained and it was loud. When Jason Bay led off the bottom of the sixth with a shot to the gap and hustled his way to third, the reaction was exactly as it should’ve been: loud, and louder. It was a 2-1 game by that point. Bay would score to make it 3-1. And soon enough it’d be 6-1, and 7-1, and it would soon be useful to remember something:

Mets fans have a rap for being fickle and flighty. But nobody ever comes to a ballpark to boo, not until provoked. Not until there’s no other alternative. Across nine innings yesterday, it wasn’t just the Mets who tried to throw whitewash all over the memory of 2009, but the fans, the people who wear those scars far deeper than the players ever will.

“There’s really nothing negative you can say about us today,” Francoeur said, beaming, and as the people streamed out of the yard and flooded the Grand Central, for the time being, it was hard to recollect 2009 all of a sudden. Healing power. Hidden magic.

Love what you’ve done to the place!

We give the Mets a hard time sometimes, because they force us to. They kept insisting last year that they got their stadium absolutely right, blanched when there were complaints, got downright testy whenever shortcomings were reported.

So it is only fair that we report that in converting half of a team merchandise store into a real, honest-to-god Hall of Fame, located adjacent to the Jackie Robinson Rotunda, the Mets didn’t only do the right thing — which they did — and didn’t just nail it absolutely perfectly — which they also did.

No, it’s better. Because if there was one thing that Mets fans were united with in their fury, it was the lack of history attached to the team’s new yard. You could walk through Citi and honestly not know who played there. Even the ushers were for some reason given burgundy get-ups that looked like the old Phillies uniforms.

And you know something? The Mets heard that outrage. And they did something about it. If you are a Mets fan, this is a place you must visit at once, and must come back to again and again. It is that good, was done that well. May I be the first to thank you, Mets fans, for insisting your voices be heard.

Now if they would only burn those god-awful usher’s outfits.

VAC’S WHACKS

JEFF Francoeur, who walks so little he gives Moneyball folks a facial tic just looking at him, walked in his second at-bat yesterday. In a related development, the wind-chill factor just plummeted in Hell.

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Darryl Strawberry looked awfully good and awfully fit in throwing out the first pitch yesterday — so much so, Jerry Manuel should have pondered putting him in the cleanup spot in place of Mike Jacobs.

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Poor Cameron Maybin. All the Marlins’ center fielder did yesterday was strike out three times, misplay three catchable flyballs — and watch Gary Matthews Jr., fighting the same wind, make it look easy.